Application of two parameter elastic-plastic fracture mechanics to analysis of structures

• Published in: Engineering fracture mechanics 1997-07, Vol.57 (4), p.431-446
• Main Authors: Joyce, James A., Link, Richard E.
• Format: Article
• Language: English
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/S0013-7944(97)00030-1

J-integral resistance curves are developed for single edge bend [SE(B)] specimens of HY80 over a range of crack length ratios from 0.13 to 0.83. The wide range of constraint present over this range of crack length ratios results in J-integral resistance curves with nearly constant initiation toughnesses as measured by J Ic, but with widely varying J- R curve slopes beyond J Ic. A nearly linear relationship is shown to exist between the slope of the material J-resistance curve after 1 mm of crack extension and the Q parameter introduced by O'Dowd and Shih (Family of crack-tip fields characterized by a triaxiality parameter: Part I—Structure of fields. Journal of Mechanics and Physics of Solids, 1991, 39(8), 989–1015) to quantify elastic-plastic constraint. The constancy of J Ic and the linear dependence of the tearing resistance on Q is used to develop an interpolation scheme to evaluate the J-integral resistance curve applicable to a specific structural application when the Q parameter can be estimated for the flaw geometry and loading present in the application.